LAND, GEOGRAPHY, WEATHER AND NATURAL DISASTERS IN LAOS

LAND AND GEOGRAPHY IN LAOS

Located in Southeast Asia in the middle of the Indochina Peninsula, and bordered by China and Myanmar (Burma) to the north, Thailand to the west, Vietnam to the east, and Cambodia to the south, Laos is a land-locked country covering 91,426 square miles (236,800 square kilometers), which is about the same size as Britain or Utah or twice the size of Pennsylvania. It has only 6.7 million people, only a few highways and vast tracts of empty land.

The Lao People’s Democratic Republic (Lao P.D.R.) as the country is officially known lies between latitude 14 to 23 degrees North and longitude 100 to 108 degrees East. The 84th largest country in the world and the only country in Southeast Asia without an outlet to the sea, Laos extends for 1,400 kilometers in a northwest-southeast direction on a rugged strip of the Indochinese peninsula. Most of the country is mountainous and thickly forested—with some plains and plateaus. The Mekong River forms a large part of the western boundary and southern with Thailand and Cambodia.

Laos has a land area of 230,800 square kilometer. More than 6,000 square kilometer is occupied by water. It has 5,083 kilometers of land boundaries: 235 kilometers with Myanmar, 541 kilometers with Cambodia, 423 kilometers with China, 1,754 kilometers with Thailand and 2,130 kilometers with Vietnam. It has no coastline or maritime claims. Elevation extremes: lowest point: Mekong River 70 meters; highest point: Phu Bia 2,817 meters. [Source: CIA World Factbook]

About six percent of the country is good for agriculture (compared to 21 percent in the U.S.) and most of this arable land is found along fertile Mekong River basin. About two thirds of the country is covered by dense tropical forests and three forths is covered by mountains. The forested land area has declined significantly since the 1970s as a result of commercial logging and expanded swidden, or slash-and-burn, farming. Laos’s location has often made it a buffer between more powerful neighboring states, as well as a crossroads for trade and communication.

Laos is roughly 1,000 kilometers (600 miles long) with parts of the southern panhande only 160 kilometers wide. The northern half of the country is covered in dense tropical rain forest, mountains that rise to over 2,000 meter and slate-black limestone karsts. In the northeast, the mountains give way to the Plain of Jars (Plaines des Jarres, PDJ), a diamond-shaped patch of dairy land covered with giant stone burial urns dating back thousands of years. The southern half of the country runs in a narrow panhandle, which empties onto the Bolovens Plateau. Down the eastern edge of the panhandle are the Annamite Corilleras, a towering mountain range that covers most of the 1323 mile border with Vietnam. On the western edge is the Mekong River, which forms a common border with Thailand, but there are also two Lao provinces on the western side of this big river.

Laos is often broken up into two major regions: Upper and Lower Laos. Upper Laos, in the northern and eastern Laos is characterized by rugged mountains, up to 2,820 meters in height, and narrow valleys. The main ridges run north to south and many of the valleys have swift flowing tributaries of the Mekong River. The area is also filled with karst scenery, caves and underground rivers. The limestone plain on which the Plain of Jars is located is relatively infertile. Some areas are covered by dense forests. Other others have been deforested by slash and burn agriculture. Northwestern Laos forms the eastern side the Golden Triangle, with Myanmar and Thailand on the other two sides.

Low Laos in the south is dominated by several plateaus. Some feature limestone karst topography, and savannah grasslands. The Bolovens Plateau in the southeast is underlaid by volcanic basalt and has fertile soils that have been exploited for plantation agriculture, mainly for coffee and rubber. Most of Laos's people live in fertile valley along the Mekong river, which defines the border between Laos and Myanmar, Thailand and Cambodia. The land around the Mekong River and south of Vientiane is relatively flat and heavily populated. The Annam Cordillera is an isolated mountain range in eastern Laos which forms the border with Vietnam. The mountains reach a height of 8,000 feet and are broken up by passes, some as low as 1,600 feet.

Topography of Laos

Topography of Laos is largely mountainous, with elevations above 500 meters typically characterized by steep terrain, narrow river valleys, and low agricultural potential. This mountainous landscape extends across most of the north of the country, except for the plain of Vientiane and the Plain of Jars in Xiangkhoang Province. The southern "panhandle" of the country contains large level areas in Savannakhét and Champasak provinces that are well suited for extensive paddy rice cultivation and livestock raising. Much of Khammouan Province and the eastern part of all the southern provinces are mountainous. Together, the alluvial plains and terraces of the Mekong and its tributaries cover only about 20 percent of the land area. [Source: Library of Congress]

The terrain of Laos is characterized by three distinct regions - mountains, plateaus, and plains. The mountains and plateaus make up three-quarters of the total area.
High mountains rising to an average height of 1,500 meters dominate the Northern region. The three highest mountains in the country are all located in the Phou Ane Plateau in Xieng Khouang Province. They are Phou Bia at 2,820 meters, Phou Xao at 2,690 meters and Phou Xamxum at 2,620 meters. The Phou Luang (Annamite Range) stretches from Southeast on the Phouane Plateau down to the Cambodian border; the others are the Nakai Plateau in Khammouane Province and the Bolaven Plateau in Southern Laos, which is over 1,000 meters above sea level.

The plain region consists of large and small plain areas distributed along the Mekong River. The Vientiane Plain, the largest, is situated on the lower reaches of the Nam Ngum River. The Savannakhet Plain is situated on the lower reaches of the Sebangfai River and Sebanghieng River, while the Champasack Plain on the Mekong River stretches out to the Thai and Cambodian borders. Blessed with rich and fertile soil, these plains represent one quarter of the total area known as the granaries of the country.

Most of the western border of Laos is demarcated by the Mekong River, which is an important artery for transportation. The eastern border with Vietnam extends for 2,130 kilometers, mostly along the crest of the Annamite Chain, and serves as a physical barrier between the Chinese-influenced culture of Vietnam and the Indianized states of Laos and Thailand.These mountains are sparsely populated by tribal minorities who traditionally have not acknowledged the border with Vietnam.

Laos shares its short--only 541 kilometers--southern border with Cambodia, and ancient Khmer ruins at Wat Pho and other southern locations attest to the long history of contact between the Lao and the Khmer. In the north, the country is bounded by a mountainous 423-kilometer border with China and shares the 235- kilometer-long Mekong River border with Burma. *

Mekong River and Laos

The Lao PDR is criss-crossed with a myriad of rivers and streams. The largest is the Mekong River, flowing for 1,898 kilometers from the North to the South, with 919 kilometers of the river forming the major portion of the border with Thailand. It is estimated that some 60 percent of all the water entering the Mekong River system originates in Laos. These rivers and streams provide great potential for hydropower development with 51 percent of the power potential in the lower Mekong basin contained within Laos. Mekong River is navigable much of length but is not navigable between the sea and Laos because of Khone Falls in southern Laos. The Nam Ou, Na That and Nam Ngum are large tributaries of the Mekong River.

The Mekong River and its eastern tributaries drain all of Laos with the exception of Samneua Province in the northeast. The 1,600 kilometers of navigable water of the river that passes through Laos or along its border is the longest transportation and communication route in the country. But rapids in the far north and far south effectively cut Laos off from the sea and cross-border and international commercial possibilities.

Most of the western border of Laos is demarcated by the Mekong River, which is an important artery for transportation. The Khong falls at the southern end of the country prevent access to the sea, but cargo boats travel along the entire length of the Mekong in Laos during most of the year. Smaller power boats and pirogues provide an important means of transportation on many of the tributaries of the Mekong. The Mekong has thus not been an obstacle but a facilitator for communication, and the similarities between Laos and northeast Thai society--same people, same language--reflect the close contact that has existed across the river for centuries. Also, many Laotians living in the Mekong Valley have relatives and friends in Thailand. Prior to the twentieth century, Laotian kingdoms and principalities encompassed areas on both sides of the Mekong, and Thai control in the late nineteenth century extended to the left bank. Although the Mekong was established as a border by French colonial forces, travel from one side to the other has been significantly limited only since the establishment of the Lao People's Democratic Republic (LPDR, or Laos) in 1975. *

With an absense of railraods and a shortage of good roads the Mekong River is a vital transportation link in Laos. All of the country’s major cities and settlements are located on or near its banks. Flooding deposits rich top soil on its banks. The narrow flood plain is one of the main wet rice growing areas.

The Mekong River flows through a narrow, 200-kilometer-long gorge in southern China and along the Myanmar-Laos. From the tripoint of China, Burma (Myanmar) and Laos the river flows southwest and forms the border of Burma and Laos for about 100 kilometres (62 miles) until it arrives at the tripoint of Burma, Laos, and Thailand. This is also the point of confluence between the Ruak River (which follows the Thai-Burma border) and the Mekong. The area of this tripoint is sometimes termed the Golden Triangle, although the term also refers to the much larger area of those three countries that is notorious as a drug producing region.

As one travels south on the Mekong its become easier to navigate and higher numbers of greater varieties of boats appear. From the Golden Triangle tripoint, the Mekong turns southeast to briefly form the border of Laos with Thailand. It then turns east into the interior of Laos, flowing first east and then south for some 400 kilometres (250 mi) before meeting the border with Thailand again. Once more, it defines the Laos-Thailand border for some 850 kilometres (530 mi) as it flows first east, passing in front of the capital of Laos, Vientiane, then turns south. A second time, the river leaves the border and flows east into Laos soon passing the city of Pakse. Thereafter, it turns and runs more or less directly south, crossing into Cambodia. At Khone Falls the river cascardes over rocks and separates into several branches, divided by forested islands, before it enters Cambodia.

Weather and Climate in Laos

Just south of Tropic of Cancer, Laos is a hot, tropical country with a monsoon climate and three major seasons: the hot, the cool, and the wet monsoon seasons. The pronounced rainy season extends from May through October. The cool dry season runs from November through February, and a hot dry season is in March and April. The temperatures are generally cooler in the highlands and in the north. In the lowlands humidity is generally high and the high temperatures are usually around 90 degrees F. The temperatures often drop into the 40s at night in the winter in the northern highlands.

Generally, monsoons occur at the same time across the country, although that time may vary significantly from one year to the next. Rainfall also varies regionally, with the highest amounts— 3,700 millimeters annually—recorded on the Bolovens Plateau in Champasak Province. City rainfall stations have recorded that Savannakhét averages 1,440 millimeters of rain annually; Vientiane receives about 1,700 millimeters, and Louangphrabang (Luang Prabang) receives about 1,360 millimeters. Rainfall is not always adequate for rice cultivation, however, and the relatively high average precipitation conceals years where rainfall may be only half or less of the norm, causing significant declines in rice yields. Such droughts often are regional, leaving production in other parts of the country unaffected. Temperatures range from highs around 40 degrees C along the Mekong in March and April to lows of 5 degrees C or less in the uplands of Xiangkhoang and Phôngsali in January.

The climate of Laos roughly divides the year in half. Beginning in late May are five months of heavy tropical rains. Five more months, beginning in December, have high temperatures and little rain. A short spring and autumn connect these rainy and dry seasons.
The yearly average temperature is about 28 degrees Celsius, rising to a maximum of 38 degrees Celsius during April and May. Rainfall is often less than five centimeters a month in the dry season and reaches up to 30 centimeters a month in the rainy season. March and April are often the hottest months with temperatures often topping 40 degrees C. In the wet season the rains help cool things down.

About 80 percent of the annual rainfall falls in the wet season, with the rainfall amounts varying according to altitude and latitude with the highlands of central Laos and the peaks of the Annamite Chain in southern Laos getting the most rain. Less rain falls in the north The average precipitation is highest in Southern Laos, where the Annamite Mountains receive over 300 centimeters and the Bolovens Plateau gets 250 centimeters annually. In Vientiane rainfall is about 150 to 300 centimeters, Luang Prabang gets about 125 centimeters a year, and the Northern provinces only 100 to 150 centimeters annually.

The "cool" dry months (December-February) are the best time to travel in Laos as a whole. The temperatures are relatively mild, the days are bright and sunny, and humidity is low. In the mountains, however, it sometimes is cold at night. In the winter a cold high-pressure zone over Tibet clashes with a low pressure zone over the Indian Ocean, bringing cold, dry winds. In Vientiane a minimum temperature of 19 degrees Celsius occurs during January. In mountainous areas, however, temperature drops to as low as 14-15 degrees Celsius during the winter months, and during cold nights, can easily reach the freezing point, especially in December and January in places loke Xieng Khouuane Province.

In the dry season, road travel is easier but the countryside is often brown, hazy and dusty, and smoky from slash and burn agriculture. In most parts of Laos the hot dry season is very hot especially in April and May, before the arrival of the monsoons, when temperatures are often above 100 degrees F everyday. This a good time of year to visit the mountains.

During the rainy season air masses from the Indian Ocean pass over Southeast Asia, releasing moisture they have picked along the way. Rains tend to fall in short afternoon downpours during the rainy season, when the countryside is lush and green and beautiful but the jungles are full of leeches and dirt roads in remote areas become impassable.

The typhoon season traditionally begins in July—but large storms can churn up as early as May—and ends in October. Although Laos sometimes experiences heavy rain this time of the year it is protected from the high winds by Vietnam (typhoons approach Southeast Asia from the Pacific).

The rainy season in Laos coincides more or less with the rainy seasons in Vietnam, Cambodia and Burma, but is different from the rainy season on the west coast of Malaysia (from September to November) and rainy season in Singapore, Borneo, Indonesia and the east coast of Malaysia (November to January). The rainy season in southern China is generally most intense in June and July.

Natural Disasters and Earthquakes in Laos

Natural hazards in Laotian include mainly floods and droughts.

An earthquake that measured 7.3 on the Richter scale occurred in a remote area of the Sino-Burmese border near Menglian and Laos in 1997.

Laos Hit by Powerful Earthquake in 2007

In May 2007 Laos was struck by a powerful earthquake that was felt as far as away as Thailand and Vietnam. The BBC reported: “The quake measured magnitude 6.1 and struck not far from the northern city of Luang Prabang, the US Geological Survey reported. Buildings swayed in both the Thai and Vietnamese capitals. People reportedly fled shopping centres and buildings were evacuated in Bangkok. However, there were no reports of damage or injuries. [Source: BBC, May 16, 2007 <>]

“The earthquake struck 155km (97 miles) west-north-west of Luang Prabang at just before 4:00pm local time, the USGS reported. The epicentre is believed to be in a fairly remote area of western Laos. But it was little felt in Luang Prabang. One resident spoke of feeling "disorientated" for a couple of minutes, while others said they felt little or no shaking. An official in the Laos capital Vientiane said the quake lasted around 10 seconds, and there were no immediate reports of casualties or damage from the area. <>

“But there were scenes of panic in the Thai capital, Bangkok, some 800km (500 miles) south of the quake zone. Many office blocks were swiftly evacuated after the earthquake shook the city, with its occupants gathering in the streets outside. "I have not seen a strong earthquake like this before, my head felt like it was spinning," Nattaya Limngern, a 40-year-old office worker, told the AFP news agency. <>

“The quake was also felt strongly in the area of northern Thailand bordering Laos. Some people were evacuated in the city of Chiang Mai. Officials said they were still checking buildings but had no reports of damage or injuries. Hundreds of kilometres to the east, in the Vietnamese capital, Hanoi, the quake was felt mostly on the upper floors of high rises. Around 700 people fled Vincom Tower, one of the tallest buildings in the city, when it started to sway, a company spokeswoman told the Associated Press. "It was shaking for about three minutes, and I think this was the strongest shaking we have ever felt," Nguyen Thu Lan said. "After the shaking stopped, many people who ran out wouldn't dare to return." <>

A magnitude 4.5 tremor occurred in the immediate region 19-hours prior to this event. The 6.3 magnitude earthquake occurred at a depth of 23 kilometers. It was followed by at least one aftershock of magnitude 4.5 at 09:31 UTC. [Source: Amateur Seismic Centre (ASC), Pune, 2013 **]

The earthquake was felt strongly in western Laos, especially in the provinces of Bekeo, Louang Nampha and Oudomxai. Several buildings were damaged, including four temples, two stupas and two schools at Houayxay and Pakhta in Bekeo Province. Many people were frightened and went outdoors at Oudomxai town in the province of the same name, where it lasted close to 10-seconds. Parked cars were seen shaking in Oudomxai. It was also felt strongly at Louang Nampha in the Louang Nampha province; people ran outdoors and one eyewitness saw "produce" falling from shelves. Some residents of Louang Prabhang reported feeling tremors and experienced spells of dizziness, that are associated with distant long-period effects of large earthquakes, for close to 2-minutes. Mild tremors were also felt in multi-storied buildings as far as the capital, Vientiane. **

Strong tremors were also experienced in northern Thailand. In the Chiang Saen district, bricks and cement were dislodged from the thousand year old Wat Prathat Chedi Luang Pagoda. A spire on the top of Wat Phra That Jomkitti Pagoda and the lotus-shaped tip of Wat Pasak Pagoda were knocked down. Cracks developed in the Jomkitti Pagoda. Buildings were shaken strongly in Chiang Rai, knocked hanging objects off walls. In the Mae Rim district, loose objects were thrown off shelves. The 5-storey Prachanukroh hospital was vacated and later declared off limits. Seismic seiches were observed in swimming pools in Chiang Mai and Chiang Rai. In the Muang district, the quake rattled windows and many people ran outdoors. Tremors were felt in much of the northern provinces of Chiang Mai, Lampang, Nan and Phayao. Locals and tourists rushed out of buildings in the city of Chiang Mai where the quake was reported to have been felt for close to a minute. The earthquake was also felt hundreds of kilometers to the south in the capital, Bangkok. Several high-rise buildings, including the offices of the Xinhua news agency and the Swedish Embassy, were evacuated, especially in the Klong Toey, Phayatai, Phetchaburi, Sathorn, Silom, Sukhomwit and Vipavadi. In an isolated incident, window panes were reportedly damaged in the top floors of the MBK building on Siam Square. On 26 May 2007, a 2-storey building that was part of a Tourist Information Center and damaged in the earthquake, collapsed in the Mae Rim district but did not cause any injuries. The structure had been evacuated after it subsided during the 16 May earthquake. **

Elsewhere in the region, strong tremors were felt in Dien Bien Province in north-western Vietnam. Tremors were also felt hundreds of kilometers away to the east in high-rise buildings in Hanoi, Vietnam; the shocks were most distinctly felt in the central districts of Dong Da, Hai Ba Trung and Hoan Kiem. People in the Vincom twin towers on Ba Trieu street, the Melia and Daewoo hotels, the Hoa Binh Tower on Hoang Quoc Viet street, the Tungshing building on Ngo Quyen, and the Prime Center left their buildings but later returned to work. In the Vincom twin towers, computers, furniture and window blinds rattled and sent office workers rushing outdoors. Tremors were also felt in Jinghong in China's Yunnan Province rattling windows for close to a minute. The effects of this earthquake in adjoining parts of the Shan State in Myanmar are unavailable. **

This site contains copyrighted material the use of which has not always been authorized by the copyright owner. Such material is made available in an effort to advance understanding of country or topic discussed in the article. This constitutes 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit. If you wish to use copyrighted material from this site for purposes of your own that go beyond 'fair use', you must obtain permission from the copyright owner. If you are the copyright owner and would like this content removed from factsanddetails.com, please contact me.